The city council spent more than £8.4 million on expert consultants last year – including £1.5 million on the tram extension before councillors have given the project the green light.

During 2017/18, £5.6 million was spent on consultants for the running of council services, while almost £2.8 million was paid to experts for capital projects including new school buildings. One company was paid almost £2 million as a bonus for helping the authority achieve savings.

More than �1.5 million was spent last year on consultancy fees for the proposed tram extension.

The amount spent on consultants was less than 2016/17 when £9.7 million was handed over to external companies. But opponents have hit out at the multi-million-pound spending, which tallied up more than £23,000 of public money a day.

Green Cllr Gavin Corbett said that, while it is good there had been a marked decrease in the total amount spent, some of the reasons behind the spending were not always clear.

He said: “The amount spent on consultancy is down a bit which is good news.

“However, at well over £8 million it is still a hefty budget and every single penny needs to be justified.

“We have all heard the quip about consultancy being when you lend someone your watch so you can ask them the time.

“So it is only valid if it brings in additional expertise not available to the council and is critical to whether a service or project works.”

He added: “In too many cases the actual impact of the work is not that clear. In other cases, I’m not sure what added value has been provided. For example, almost £800,000 has been spent on consultants for savings on asset management but the budget remains significantly off-track.

“A large and complex organisation like the council certainly needs outside expertise from time to time, but there is still a way to go in getting it to the right level.”

A total of £1.9 million was paid by the council to Ernst and Young last year as a “gainshare fee for benchmarking” in helping the authority to save £150 million between 2013/14 and 2017/18.

WYG Environment Planning Transport Ltd were paid £110,740 for a George Street and New Town consultancy design works for the proposed city centre transformation programme, which could see key roads closed to traffic.

Conservatives have criticised the SNP-Labour administration for spending more than £1.5 million on consultants working on the extension of the tram line, which councillors won’t decide whether to go ahead with until December. Atkins Ltd was paid £466,905 as a technical design advisor, Steer Davies and Gleave received £131,356 for tram traffic modelling and Turner and Townsend has already been paid £719,380 for project and commercial management of the prosed extension.

Cllr Andrew Johnston said: “While I welcome the slight reduction from the previous year, that £5 million of revenue is an awful lot when we are facing another difficult budgeting process for next year.

“It’s completely unreasonable for the council to be taking forward the next stage of the tram extension before the results of the Hardie inquiry are known. It does not make sense to be front-lining spending on it, before we have a clearer picture.”

The council said work started following approval by councillors to begin some of the next phase of the tram.

Finance and resources convener, Cllr Alasdair Rankin, said large consultancy fees were to be expected.

He said: “Spend on consultants is closely monitored by the council to ensure that we get best value for Edinburgh’s tax payers.

“Plans to proceed with stage two of the Edinburgh tram project were approved by council in September 2017 and this included consultant costs to provide professional advice as you would expect for this major project.”